using Se before intransitive verbs

Question

Consider the following sentences that sparked the confusion I now face.

El sol secó la ropa. The sun dried the clothes

La ropa se secó al sol. The clothing dried in the sun

In the second sentence, se is used before the intransitive verb secar.

Researching why, I found the link Reflexive pronouns and intransitive verbs. In which the following explanation was given.

Unlike English, if you say "la ropa secó...", any Spanish speaker would wonder "secó... ¿qué o a quién?" because this verb is not used as intransitive, even if you omit the direct object. That "se" turns the verb into intransitive and solves the problem. English can easily turn transitive verbs into intransitive by just omitting the direct object, but in Spanish this object is assumed to be implicit if not present.

From the above explanation, my understanding is that se indicates that the verb being used is intransitive rather than transitive. The problem however, is that I can think of a few sentences where a verb that can be both transitive and intransitive is used intransitively but se is not used as in the following.

Llama cuando quieras. Call when you want.

Cuando llegué, la tienda ya estaba cerrada. When I arrived, the store was already closed.

Ella practica a menudo. She practices often.

I hope that I am clear in my explanation that I am not asking about the impersonal se or when se is used to show something is done by accident etc... since these may also go before an intransitive verb. Rather I am asking why/how do you know when some intransitive verbs require "se" to differentiate it from its transitive counterpart and when it doesn't.

I have read the following questions that have been asked before. When is “se” used before a verb? and when se is needed for transitive verbs?

Answer 1

Short answer is: you have to learn it by heart. Longer answer follows.

There's a certain pattern you can take advantage of. Secar belongs to the same group as abrir, cerrar, quemar, arrojar, derrumbar and a lot of others verbs that are transitive when used as such, and intransitive when followed by the reflexive pronoun. Therefore they're a type within so-called pronominal verbs. You'll find these marked as such in dictionaries. The DLE (the dictionary of the Royal Academy) marks them as tr. (transitive) followed by U. t. c. prnl. = úsase también como pronominal = "used also as pronominal". This is not exactly helpful for a foreign language student.

In some cases the English equivalents of these verbs are also ambitransitive, although English doesn't mark the intransitive usage with a pronoun: such is the case of abrir "open, open up", cerrar "close, close down", etc.

In other cases English might prefer an active vs. passive alternation: for both quemar and quemarse English has "burn", but a natural translation will often use "get burned" for Spanish quemarse.

What these verbs have in common, semantically, is that the patient of the action is obligatory (i.e. the door or window that opens or closes for abrir or cerrar must appear somewhere because it's central to the action), while the agent (the one who opens or closes the door or window) is not. If you choose to specify the agent, then you have the plain verb in a transitive sentence: Ella cerró la puerta "She closed the door." If you don't specify the agent because you want to emphasize that the event took place spontaneously (or the agent is inanimate, such as the wind), then you use the intransitive pronominal verb: La puerta se cerró "The door closed." (But addenda below).

This is very close to what's called voz pasiva refleja, which is the structure used in sentences such as La casa ya se vendió "The house is already sold." It's subtly different because in this case it's obvious that the house didn't sell itself: it was sold by some animate agent. But the syntax is the same.

ADDENDUM: As pointed out in the comments, abrir without se can also be intransitive: El museo abre a las 11. The same goes for cerrar. This somewhat complicates the issue. Note however that this intransitive use of abrir is only employed together with a reference to the time or manner of the action, as in La puerta abre hacia adentro. It also suggests habitual action (El museo abre a las 11 means the museum always opens at 11; La puerta abre hacia adentro means the door is built in such a way that it always opens towards the inside). Such complication doesn't exist with other verbs like derrumbar ~ derrumbarse (English: "to bring down" ~ "to come down").

Answer 2

This type of use of se can be thought of in English as

to become or to get

Examples:

Me aburro | I become/get bored

Me canso | I become/get tired

Me impaciento | I become/get impatient (also, of course: I'm getting impatient)

In the case of the clothing -- it becomes dry. Also, it gets dry; it's getting dry.

Answer 3

I am afraid you will have to learn which verbs are reflexive by heart.

In Spanish some verbs are just reflexive and need this reflexive particle, which for the 3rd person is "se". You would as well say "me he secado" when referring to the first person or "no uses la toalla, sécate al sol" for the 2nd person.

Some verbs which are usually reflexive :

• "aburrirse" to get bored
• "durcharse" to get a shower
• "enamorarse" to fall in love
• "reirse" to laugh

There are verbs which have different meanings, depending on wether you use them in reflexive form or not. Some of these verbs I can think of right now would be:

• "irse" to go away, against "ir" to go
• "dormirse" to fall asleep, against "dormir" to sleep
• "meterse" to take on somebody, against "meter" to introduce
• "encontrarse" to meet, against "encontrar" to find

It is not clear to me whether these usages are intransitive or the direct object refers to the subject. I think it is easier to remember that usage is like this. Some verbs are reflexive, some aren't, some can have it both ways, and their meaning can change quite a bit.

You can find a good explanation here